Terrible VN hidden as a "RPGMaker" game.
Very bad NTR Quality. It's a weird mix between Netorare and Netorase, the plot makes even less sense than your typical NTR game (and that's a feat in itself tbf).
The Janitor sees you and your GF fucking in some storeroom. He asks YOU and your GF "hey, give me your GF for 30 days and I'll forget it". And ofc you say yes (because if you say no, you have a game over with a black screen as an ending).
Since you KNOW your girl will get fucked for 1 month, the game clearly oriente itself as a Netorase Game, but it seems it wants to "play" its story as a Netorare one, and everything falls apart.
Corruption build-up is really bad paced. You play as the girl first, see the corruption of 1 month of fucking with the old man in like 10mn with 0 gameplay. You move the GF from her bed to the house of the old guy, that's the "gameplay". And don't think you can go elswhere, there's nothing out of the old guy house in the "Girl Part". (Oh, you buy condom one time, 15 seconds gameplay, sorry)
Then you play as the guy. That's when the "NTR" element should shine for some people : Chasing the girlfriend, discovering if she's fucking the old guy, or find an alusion of it with shadows scenes, like Raiogar, Scar of Summer...
Except the game does nothing of that. You just go home everyday (aside for one day or two), sleep, dream about what your girl could do, and that's it until the ending.
Oh, you can talk to your classmate to hear some rumors... That's about as much as you'll get.
Then you have 2-3 mn of "gameplay" at the ending B where you actually search, find and see your GF fucking the janitor.
Oh, and don't get excited by the "SNS" part. You have NOTHING of it during 95% of the game, and then all the SNS messages are sent to you in like 30 seconds during the endings.
3-4 for choices through the entire game which will rail you on a specific ending (1 of which is useless and without H-scene, the reward being a black screen explaining how pathetic the MC is even when you do the "right choices".).
TLDR: Complete waste of time, not even worth a MTL.